LTC2978
APPLICATIONS INFORMATION
2
Connecting the USB to I C/SMBus/PMBus Controller
Figures 30 and 31 illustrate application schematics for
powering, programming and communicating with one or
to the LTC2978 in System
2
more LTC2978's via the LTC I C/SMBus/PMBus controller
2
The LTC USB to I C/SMBus/PMBus Controller can be
regardless of whether or not system power is present.
interfaced to LTC2978s on the user's board for program-
ming, telemetry and system debug. The controller, when
used in conjunction with LTpowerPlay software, provides
a powerful way to debug an entire power system. Failures
arequicklydiagnosedusingtelemetry,faultstatusregisters
and the fault log. The final configuration can be quickly
developed and stored to the LTC2978's EEPROM.
Figure30showstherecommendedschematictousewhen
the LTC2978 is powered by the system intermediate bus
through its V
pin.
PWR
REPEAT OUTLINED CIRCUIT FOR EVERY LTC2978
4.5V TO 15V
150k
49.9k
V
PWR
0.1µF
LTC2978
ISOLATED 3.3V
V
V
DD33
DD33
SCL
Si1303
GND
0.1µF
0.1µF
SDA
V
DD25
TO LTC USB TO
I C/SMBUS/PMBUS
CONTROLLER
PIN CONNECTIONS
OMITTED FOR
CLARITY
2
10k
10k
5.49k
SCL
SDA
SHARE_CLK
WP GND
TO/FROM OTHER
LTC2978s
2978 F30
Figure 30. LTC Controller Connections When VPWR is Used
2978fc
74
Linear Systems [ Linear Systems ]
